# How are covalent compounds named?

May 5, 2014

Covalent compounds are molecules formed by non-metals bonded together by sharing electrons.

Covalent compounds are named by using numerical prefixes to identify the number of atoms in the molecule.

For example Carbon Dioxide $C {O}_{2}$ and Carbon Monoxide $C O$.
Carbon Dioxide has one carbon atom and two oxygen atoms as identified by the prefix di = 2. Carbon Monoxide has one carbon and one oxygen as identified by the prefix mono = 1.

The numeric prefixes are

mono = 1
di = 2
tri = 3
tetra = 4
penta = 5
hexa = 6
hepta = 7
octa = 8
nona = 9
deca = 10

In the naming, never use mono- for the first element.
The first element keeps its name.
The second element always end in the suffix -ide.
Drop the double vowel for the prefix and the element of the second element in the compound.

Here are some more examples for covalent compounds.

${N}_{2} {O}_{5}$
Dinitrogen Pentoxide

$C C {l}_{4}$
Carbon Tetrachloride

${P}_{3} {F}_{6}$
Triphosphorus Hexafluoride

Acids are named differently, as are organic compounds and some common other compounds. However, for the vast majority of covalent compounds, this should have you covered.